Improvement in apparatus for coating metal plates



E. MOREWOODXE J. H. ROGERS. APPARATUS FOR COATING METAL PLATES.

No.171,687. Patented Jan. 4,1876.

EDMUND MoREwoon, 0E LLAN LLYZ,

AND JOHN H. ROGERS, OF LLANGEN- NEon PARK, NEAR LEA-NELLY, GREAT BRITAL.

IMPROVEMENT IN APPARATUS FOR COATING METAL PLATES.

Specification forming part of Letters Patent No. 171,687, dated January 4, 1876; application filed l I December 6, 1875.

f CASE .0.

of Llanelly, and J OHN HENRY ROGERS, off

Llangennech Park, near Llanelly, both in the county of Oarmarthen, Great Britain, have in vented an Improvement in Applying Tin or other Metal to Metal Sheets and other surfaces of metal; and the following is declared to be a full and correct description of the same.

Our present invention consists in passing the sheets, after leaving the coating metal or flux, through a heated chamber, between troughs containing coating metal or flux, or both, so as to allow the surplus coatingmetal to draw or drain from the sheets, and then to pass them between rollers revolving in coating metal or flux, which may be of a better quality than that in the bath, in order that, such sheets may receive a finishing coating, or that the coating may be reduced and equalized by said rollers.

In the drawing, Figure 1 is a vertical section of our apparatus, and Fig. 2 is a similar view of a slight modification thereof.

a a, Fig. 1, are a pair of coated rollers, suitably driven and revolving in contact with each other. They dip into melted coating metal, in troughs b b, and this metal should be of the best quality to give a fine surface and finish to the plates. Between the troughs b b, and above the surface of the coating metal in the pot 0, there is a hot-air chamber, (1, and the air of this chamber is heated by the radiation of heat from the coating metal in said pot c and from the sides of the trough b,

and through this hot-air chamber the sheets are passed as they emerge from the coating metal in said bath 0. The hot-air chamber may be formed partly of the sides of the troughs and partly by wall-surfaces below same. Behind the rolls we place flux to keep the surface of the rolls in good order, and the flux at e is confined to the back of the rolls by the liquid metal, into which the rolls dip, and by guards or partition-pieces f f, which fit against the sides of the troughs b and against the rollers a a, entering grooves formed near the ends of the rollers, whereby the flux is excluded or shut off from between the said withdrawing rollers. They also fit into one another by feather and groove, as shown in Fig. 3, and may also serve the purpose of keeping coating metal or flux between a pair of rollers separate from the other coating metal or flux in the bath or trough. Care must be taken'to make them stout enough to prevent their warping.

The flux behind the rollers is, .by preference, of different quality from that used in the coating-bath, and it should be of a very fluid nature, so as to keep the finishing-rollers clean and not to adhere to the plates, in order that the plates may require little or no subsequent cleaning. For finishing tin and terne plates the flux we use is clean, fresh palm-oil or tallow, and when it becomes stale it is transferred to the first coating or other pots. We find that a great depth of fluid flux is preferable to a thin layer of thick flux, and that the partitions f f enable us to use such thin flux, whereas the partitions referred to in the British patent specification N o. 942, of 1869, were only suitable for a thin layer ofthick flux.

The metal in the troughs b b is kept melted by causing them to dip into heated flux or metal contained in the outer pot c, which may be the pot in which the plates are coated, or through which the plates pass in the process of finishing, or they may have been coated in a separate pot. When the rollers a dip into coating metal we prefer to keep the flux to the level here shown.

Any ordinary lifting device may be employed for lifting the plates out of the fiux or metal contained in the pot c and presenting them to the rollers a.

As the plate rises through the hot-air chamber d the superfluous metal drains off it, and, in passing between the rollers 64, the coating is equalized and finished. The rollers a, whose lower parts thus dip into the coating metal, or which revolve in contact with it, may either act directly upon the plate passing between them, or they may revolve against other rollers, whose surfaces they keep in proper working order, and then the latter act upon the plate as it passes up between them to improve and finish the coating upon it. This arrange ment is shown in Fig. 2, where a a are rollers driven at the same surface speed as the rollers a a, and revolving in contact with them, and in this way the surfaces of the withdrawing rollers a are kept in proper order Without bringing them into direct contact with the body of the melted coating metal and flux in the troughs b. The necks of the rollers a,

pass over or through the partition-piece f.

The,troughs may be of sufficient length to receive the spur-wheels, by which they are driven, and beneath the troughs and rollers a second set of troughs and rollers may be employed, in which caselthe upper set of troughs Instead of having coating metal in the troughs of the finishing-rollers, we sometimes substitute grease or flux of the quality and in i may be heated by fines.

. the condition most suitable for finishing the coated plates passing up between the coated rollers, which, in that case, carry round on their surface the flux supplied from such troughs, and impart, with its assistance, the

required color and surface to the coating, and reduce the weight of the coating on the plates as they pass up between the rollers.

Terne plates may thus be advantageously finished with fresh grease flux; and we may use a larger proportion of tin in the terne mixture for finishing than for earlier stages.

Metal bands may be operated upon the same as metal plates. When coating wire, grooved rollers should be used.

We claim as our invention- 1. The hot-air or draining chamber (1, formed by the troughs b b and rollers a or a and a, as set forth. y

2. The finishing: rollers a, revolving in troughs b, and thereby supplied with metal or alloy or flux separate from the flux,.metal,

or alloy 0 in the coating or grease pot, substautially as set forth.

3. The partition-pieces ff, fitting against the sides of the troughs b, and in grooves in the rollers a, and operating substantially as set forth.

' EDMUND MOREWOOD.

J. H. ROGERS.

Witnesses:

I. BEACON PHILLIPS,

Bank, Lltmelly. B. WILLIAMs,

Servant to B. Jones, Llcmelly. 

